#include <stdio.h>
int main(void)
{
    printf("Enter a dollar amount: ");
    int amount;
    scanf("%d", &amount);
    int a20, a10, a5, a1;
    a20 = amount / 20;
    amount = amount - a20 * 20;
    a10 = amount / 10;
    amount = amount - a10 * 10;
    a5 = amount / 5;
    amount = amount - a5 * 5;
    a1 = amount;
    printf("$20 bills: %d\n", a20);
    printf("$10 bills: %d\n", a10);
    printf(" $5 bills: %d\n", a5);
    printf(" $1 bills: %d\n", a1);
    return 0;
}